1. Field
The present application relates generally to wireless communications, and more specifically to systems, methods, and devices for receiver based clear channel assessment.
2. Background
In many telecommunication systems, communications networks are used to exchange messages among several interacting spatially-separated devices. Networks may be classified according to geographic scope, which could be, for example, a metropolitan area, a local area, or a personal area. Such networks would be designated respectively as a wide area network (WAN), metropolitan area network (MAN), local area network (LAN), wireless local area network (WLAN), or personal area network (PAN). Networks also differ according to the switching/routing technique used to interconnect the various network nodes and devices (e.g. circuit switching vs. packet switching), the type of physical media employed for transmission (e.g. wired vs. wireless), and the set of communication protocols used (e.g. Internet protocol suite, SONET (Synchronous Optical Networking), Ethernet, etc.).
Wireless networks are often preferred when the network elements are mobile and thus have dynamic connectivity needs, or if the network architecture is formed in an ad hoc, rather than fixed, topology. Wireless networks employ intangible physical media in an unguided propagation mode using electromagnetic waves in the radio, microwave, infra-red, optical, etc. frequency bands. Wireless networks advantageously facilitate user mobility and rapid field deployment when compared to fixed wired networks.
The devices in a wireless network may communicate information between each other. As part of communicating, devices may make a determination whether a communication channel is available for communicating data in the geographic region the devices are communicating. Typically, a transmitting device will listen to see if it can detect any traffic on the communication channel it plans on using to transmit data to a receiving device as part of a clear channel assessment (CCA). If there is no traffic, the transmitting device determines the channel is clear in the area that the transmitting device plans to transmit, and therefore can communicate data to the receiving device. Such CCA performed at the transmitting device, however, can lead to issues where the transmitting device determines a channel is clear for transmitting to the receiving device when it is not, and also where the transmitting device determines a channel is not clear for transmitting to the receiving device when it is clear. Accordingly, systems, methods, and devices for improving CCA are desired.